China Oilfield Services Ltd. (COSL) is preparing a large-scale offshore fleet expansion program with plans to add 57 new offshore support vessels, representing one of the largest expansion initiatives by a domestic energy services company in recent years.
The state-backed contractor issued a procurement notice effective from 19 to 26 May seeking proposals for preliminary and basic design services related to the planned fleet additions. The proposed program includes 13 anchor-handling tug supply vessels (AHTS) and 44 platform supply vessels (PSVs).
The 13 AHTS vessels are divided across three power categories. The plan includes four units with 15,000 horsepower, six units with 12,000 horsepower and three units with 8,000 horsepower. These vessels are intended to support offshore structures and mobile drilling units while also performing supply, standby and firefighting duties in China’s coastal waters.
The PSV segment accounts for the majority of the expansion program. The vessels are divided into three deadweight classes, consisting of 23 vessels at 3,000 deadweight tonnes, 14 vessels at 2,000 deadweight tonnes and seven vessels at 4,000 deadweight tonnes. All PSV units are planned with LNG-diesel dual-fuel propulsion systems.
Selected PSV vessels will also include DP-1 or DP-2 dynamic positioning systems to support offshore operations requiring higher positioning accuracy. These ships serve as critical offshore logistics assets, transporting drilling mud, water, fuel, tubular products and operational supplies to offshore platforms and drilling installations.
The adoption of dual-fuel propulsion across the full PSV segment reflects increasing attention to fuel efficiency and emissions performance in future vessel design. However, the current procurement process is limited to preliminary and basic design work and does not yet include construction tenders.
Final investment decisions and shipyard selection are expected to proceed following additional approvals. With a planned total of 57 vessels across two major offshore support categories, the initiative represents a broader fleet development strategy rather than a standard replacement cycle.
COSL currently operates one of the largest offshore service fleets in the Asia-Pacific region. Its fleet includes 13 geophysical and survey vessels, 57 drilling units comprising jack-up drilling rigs, semi-submersible drilling rigs, accommodation platforms and modular drilling rigs, in addition to more than 130 offshore support vessels.
